Hot magnetic halo of NGC 628 (M 74)

In several spiral galaxies that are observed face-on, large-scale ordered magnetic fields (the so-called arms) were found. One of the explanations was action reconnection, which leads to a higher ordering fields. Because it simultaneously converts energy into thermal surroundings, reconnection has been considered as heating mechanism interstellar medium for many years. Until recently, no clear observational evidence this phenomenon We search possible signatures gas by effects in radio and X-ray data face-on galaxy NGC628 (M74), presents pronounced arms vertical The strengths densities field derived, temperatures hot gas, disk halo emission. regions arms, order lower density is found than stellar arms. global temperature roughly constant throughout disk. comparison findings with those obtained starburst M83 suggests may be present NGC628. joint analysis properties also provided clues tidal interaction companion galaxy.